The Ups and Downs of Sea Level

Guest Post by Willis Eschenbach

Much has been made in AGW circles of the sea level forecast of Vermeer and Rahmstorf, in “Global sea level linked to global temperature” (V&R2009).  Their estimate of forecast sea level rise was much larger than that of the IPCC Fourth Assessment Report (FAR). Their results have been hyped at places like RealClimate as being much more realistic than the IPCC estimates.

So I figured I’d see how Vermeer and Rahmstorf are faring to date. Their results for each of the IPCC “scenarios” are archived here, and the first thirty years of their estimates are presented along with nearly twenty years of actual observations in Figure 1.

Figure 1. Satellite-based sea level observations (blue line), along with the V&R2009 sea level estimates corresponding to the various IPCC future scenarios. Sea level observations from the University of Colorado. PHOTO SOURCE

So … how are the V&R2009 predictions holding up?

Well, … or to be accurate, not well. As you can see, the observations showed an actual sea level rise that is below the lowest of the V&R2009 estimates from the lowest of the IPCC scenarios.

At present, assuming that the distance between their “best” estimate and their “lower” estimate is two standard deviations, the data is now more than four standard deviations below the “best” V&R2009 estimate.

So in answer to how their forecasts are faring, the answer is … very poorly. Abysmally, in fact. Actual observations are lower by four standard deviations than the V&R2000 “best” estimate, and are two standard deviations lower than their “lower” estimate.

w.

Technote 1 – The Colorado folks have recently included a 0.3mm/year increase in sea levels in their results. They say (possibly correctly) that this is necessary to adjust for the sinking of the ocean floor with the increasing weight of sea water from the melting at the end of the last ice age. However, since neither the IPCC nor the V&R2009 figures include that adjustment, I have not included it in this analysis so that we can compare apples to apples.

Technote 2 – I have aligned the Colorado observational results so that their trend line is zero in 1990, in order that they can be compared directly with the V&R2009 results, which have 1990=0 as their starting point. This also aligns the starting observations with the V&R2009 “best” estimate.

Technote 3 – some folks felt that my last post, “Yes, Virginia, there is an FOIA” was short on science content and long on passion … hey, what can I say, I’m a passionate guy. I trust this post will redress the balance in their estimation.

[UPDATE] Steven Mosher has graciously pointed me to a stunning disassembly of V&R2009, at the blog Climate Sanity. Makes my effort above look simplistic by comparison. He shows, among other things, that the V&R formula for sea level leads to ridiculous results when it is fed with actual data rather than IPCC scenarios … quite lethal to their claims. Well done, that man. – w.

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109 thoughts on “The Ups and Downs of Sea Level

  1. So, by the metric of “will the multi-year trend be upwards” they did pretty well I’d say. :)

  2. The easy ice has already been melted.

    Repeat after me.
    The easy ice has already been melted.

    I need a T-shirt!

  3. @fredb

    Yes, what a silly comment. It’s been upwards since the last ice age. And, we’re supposed to be alarmed that it continues to do what it’s done for thousands of years?

  4. Oh my goodness! What have you done??? The line you show as blue should have been mustard yellow, and above the tangled spaghetti mess………

  5. Be afraid, be very afraid… “In addition, Yin explained, if floating ice along the coastal areas melts it will allow the flow of glaciers to accelerate, bringing more ice into the seas.”
    And more ice in the sea is supposed to warm it perhaps… LOL

    —-

    .Warming ocean could melt ice faster than thought
    By RANDOLPH E. SCHMID – AP Science Writer | AP – 2 hrs 24 mins ago
    ….tweet3EmailPrint……WASHINGTON (AP) — Warming air from climate change isn’t the only thing that will speed ice melting near the poles — so will the warming water beneath the ice, a new study points out.

    Increased melting of ice in Greenland and parts of Antarctica has been reported as a consequence of global warming, potentially raising sea levels. But little attention has been paid to the impact of warmer water beneath the ice.

    Now, Jianjun Yin of the University of Arizona and colleagues report the warming water could mean polar ice melting faster than had been expected. Their report was published Sunday in the journal Nature Geoscience.

    While melting floating ice won’t raise sea level, ice flowing into the sea from glaciers often reaches the bottom, and grounded ice melted by warm water around it can produce added water to the sea.

    “Ocean warming is very important compared to atmospheric warming because water has a much larger heat capacity than air,” Yin explained. “If you put an ice cube in a warm room, it will melt in several hours. But if you put an ice cube in a cup of warm water, it will disappear in just minutes.”

    In addition, Yin explained, if floating ice along the coastal areas melts it will allow the flow of glaciers to accelerate, bringing more ice into the seas.

    “This mean that both Greenland and Antarctica are probably going to melt faster than the scientific community previously thought,” co-author Jonathan T. Overpeck said in a statement.

    Overpeck, co-director of the University of Arizona’s Institute of the Environment, said: “This paper adds to the evidence that we could have sea level rise by the end of this century of around 1 meter and a good deal more in succeeding centuries.”

    The subsurface ocean along the Greenland coast could warm as much as 3.6 degrees Fahrenheit (2 Celsius) by 2100, the researchers reported. The warming along the coast of Antarctica would be somewhat less, they calculated, at 0.9 degree F (0.5 C).

  6. Hmm, Vermeer says in http://www.realclimate.org/index.php/archives/2010/04/science-story-the-making-of-a-sea-level-study/

    Wow. Introducing the b term had already improved the Pearson correlation r of fit from 90% for Stefan’s original relationship to 97%; nice, but hardly on its own compelling. Bringing in the Chao et al. man-made reservoir correction brought it up to 99.2%!

    Slowly it dawned upon me that, hey, maybe I’m on to something real here, something based in physics: it seems the world ocean can be a remarkably good global thermometer, once you get to know its quirks.

    So, is this like a stock market “solution” that does great with a hindcast and poorly with a forecast? Perhaps. Vermeer does reference fitting an elephant which notes “I (Freeman Dyson) remember my friend Johnny von Neumann used to say, with four parameters I can fit an elephant, and with five I can make him wiggle his trunk.”

    Colorado’s new 0.3mm/year increase in sea levels makes me suspicious in their sea level measurements. They’re adding a new parameter without a compelling physical story. One thing I like about the Klotzbach/Gray seasonal hurricane forecasts is that they’re always trying to fewer things to include in their forecasts.

  7. Willis, are the observations based on Envisat?
    I don’t think Envisat is measuring sea level as much as it’s measuring gravity. According to Envisat, water is piling up exactly where GOCE says it should. ;)

    In their 2008 report, they say they adjusted Envisat in the beginning to match Jason. Jason was going up, Envisat was going down. So they adjusted Envisat to go up.
    Then tweeked it again in 2008, and it started going down again……….

  8. So having walked across the room and picked it up and brought it back you found it rather FAR fetched so to speak. Oh, I sea.

  9. WRT Technote 1 above

    “The Colorado folks have recently included a 0.3mm/year increase in sea levels in their results. They say (possibly correctly) that this is necessary to adjust for the sinking of the ocean floor with the increasing weight of sea water…”

    If the Ocean floor were sinking due to the increased mass of the ocean, wouldn’t the pressure cause a lifting of the unencumbered landmasses as a type of pressure offset mechanism?

  10. Looks like the models all assume exponential increases. If the models are wrong, that will be obvious soon, if not already (meaning with this post). The hope is to keep the hype going long enough to secure the government control the greens want.

    We already know that socialist economies fail eventually. That is because people teach important lessons to their children and share information with each other. As long as we teach our kids important lessons, like the basics of right and wrong, and we can communicate with each other in fora like this, we should be fine.

    Oops, maybe we have a little problem there. US Dept. of Education, indoctrination of our kids at the expense of teaching. Cybersecurity, eventual replacement of internet with powerline broadband they control, probably like China. Hate speech as a way to selectively harass and prosecute people for sharing their beliefs. UN Convention on the Rights of the Child, taking authority over our kids away from parents.

    The list in fact goes on and on. Freedom will be gone unless more than just the people here start to understand the real scope of the threat and resist. There is just a little more at stake than scientific integrity. However, we do have to start with that to undermine their foundation.

  11. Nature (as in the “mother” not the science journal) loves to falsify CO2 Climate Doomsday Rapture Prognosticators. It seems to be a joyous pastime of hers (no entity intended nor implied; mother nature is just a figure of speech).

  12. Here is what IPCC 2007 says about one aspect of sea level estimates.

    8.3.2.2 Simulation of Circulation Features Important for Climate Response
    The MOC (meridional overturning circulation) is an important component of present-day climate and many models indicate that it will change in the future (Chapter 10). Unfortunately, many aspects of this circulation are not well observed.

    It is likely that the relatively poor Southern Ocean simulation will influence the transient climate response to increasing greenhouse gases by affecting the oceanic heat uptake. When forced by increases in radiative forcing, models with too little Southern Ocean mixing will probably underestimate the ocean heat uptake; models with too much mixing will likely exaggerate it. These errors in oceanic heat uptake will also have a large impact on the reliability of the sea level rise projections.
    http://www.ipcc.ch/publications_and_data/ar4/wg1/en/ch8s8-3-2-2.html

  13. Here’s a copy of my note the the University of Colorado staff on their unfortunate conversion from “level” to “volume”:

    The simple, unvarnished fact is that your published chart is entitled “Global Mean Sea Level”. It is not entitled “Global Mean Sea Volume”. With all the media hysteria associated the practical effects of rising sea levels (which rise has been grossly exaggerated in the news), how could you not have anticipated an uproar when you revised one of the few sources showing just what that rate of rise actually is in a way that increases the rate beyond that actually measured?

    Sea volume and sea level are not one in the same and I think it disingenuous of you to pretend to think otherwise. I’ve referred to your site for years as the one place I felt ACTUAL SEA LEVELS were being reliably reported with no “agenda” fouling the data presentation. I can no longer do that now that one must read the fine print to discover that “level” is no longer actually “level”.

  14. So, essentially, when the ocean floor sinks the sea rises even more. I can really visualize it: Mann and his schtick rising to even greater heights by the second in a pool of quicksand.

  15. I don’t care about sea level rise or fall. On this 4th of July weekend I care about strawberry pie. :)

  16. Is there a set of data to chart in parallel that shows the decrease in land ice, expansion of sea through warming and any gap between the three ie Lost land ice + expansion – seabed sinkage – land rise(post ice) = sea level rise. And how does it all relate to Trenberth’s travesty of lost energy. Does it all add up in the models? If not then surprise, surprise, they are wrong (being the polite phrase).

  17. Re the Colorado adjustment. Such “adjustments” cannot cause flooding. The sole point of the adjustment is to cause panic.

  18. I was watching “Run Silent Run Deep” last night and thinking about how the models just didn’t look right in the ocean scenes. Too bad Hollywood isn’t the only ones faking it.

  19. I’m a little confused and this may be a dumb question but…

    If this study was published in 2009 then weren’t all their projections known to be wrong at the time of publishing?

  20. Sea levels are dropping, faster than previously unimagined.
    Imaginations ran wild with a perceived endless trend, which is why there is now a 4 sigma deviation from reality.
    All that has to happen for sea levels to drop rapidly is for the extra-cold winters ice to mix with the remaining anomalously warm waters that upwelled in the last El Nino.

  21. I think that 0.3mm/year adjustment is the most illogical thing they could put forward. I’m disappointed that I haven’t seen more discussion of its merits, or lack of.

    The number is a suspiciously round number. Are they sure its not 0.25mm/year, or 0.325mm/year. It just seems like a really stupid proposition to have put forward, and indefensible on the face of it.

    I say measure what’s happening always. With there system in place, in 20 years time and the cold starts hitting hard, how on earth are they going to manage a varying adjustment to account for more ice forming. It becomes unmanageable, and surely unprovable.

  22. There were so many problems with Vermeer and Rahmstorfs model that it made my head spin.

    It results in bizarre consequences, which by themselves disqualify it. For example, see the test cases here…
    http://climatesanity.wordpress.com/2010/04/03/rahmstorf-2009-off-the-mark-again-part-3/
    and here…
    http://climatesanity.wordpress.com/2010/04/12/rahmstorf-2009-off-the-mark-again-part-4-parallel-universes/
    and here…
    http://climatesanity.wordpress.com/2010/04/14/rahmstorf-2009-off-the-mark-again-part-5-variation-of-gamma/
    and here…
    http://climatesanity.wordpress.com/2010/09/07/rahmstorf-2009-off-the-mark-again-part-7-constant-sea-level-rise-rate/

    The second term of their model (b dT/dt) forces a nonsensical temperature scenario for the last decade and half to reproduce the observed satellite data and nearly impossible temperatures for the coming decade to maintain 3mm rise per year. See here…
    http://climatesanity.wordpress.com/2010/05/27/rahmstorf-2009-off-the-mark-again-part-6-satellite-data/
    for more math details see here…
    http://climatesanity.wordpress.com/2010/06/11/rahmstorf-2009-off-the-mark-again-part-6-and-a-half-gory-details/

    They used sea level data that had been already been superseded by the sea level data’s authors. Had they used the updated data with a correction for groundwater depletion, their model predicts sea level rise for the 21st century that is half of what they published. See here…
    http://climatesanity.wordpress.com/2010/11/28/rahmstorf-2009-off-the-mark-again-part-10-sea-level-projections-exaggerated-by-factor-of-2/

    The code for their model, which was archived by the National Academy of Sciences has at least one laughably bad error. See here…
    http://climatesanity.wordpress.com/2011/02/13/rahmstorf-2009-off-the-mark-again-part-12-a-mathematical-comedy/

  23. “Technote 1 – The Colorado folks have recently included a 0.3mm/year increase in sea levels in their results. They say (possibly correctly) that this is necessary to adjust for the sinking of the ocean floor with the increasing weight of sea water from the melting at the end of the last ice age.”

    I have found this a red herring for a few reasons that need further investigating. Ignious rock from volcanoes cooling from lava under the ocean very likely have a larger affect than just the weight of the water. This rock displaces water and reduces the ocean volume and is significant contribution towards the rising of ongoing sea levels. Why we know this is because not just of the rock cycle, but periods of recent glaciation (1950’s to 1970’s) and stable global temperatures have made very little difference to the rate. (based on traditional methods) Increasing weight of sea water from the melting at the end of the ice age is not the only factor. In this case displacing the volume doesn’t increase the weight of sea water, increases sea levels proportional to rising ocean beds.

  24. Thanks Willis
    With Vermeer and Rahmstorf’s mid projection of 9 vs reality of 5.5, shall we say that is a ‘bit high”?
    If we compare V&M’s rapid rate of rise in Fig. 3, vs actual recent decline it appears even the short term direction is off. It would be very helpful if you could also show the rate of change.

    One ongoing evaluation is on the “skill” of IPCC’s Global warming models to forecast future temperatures. Lucia Liljegren at The Blackboard is statistically testing this “skill” and finds it increasing wanting. See her category “data comparisons”. e.g. May T Anomalies: Cooler than April. 29 June, 2011 (12:10) e.g. 25 month smoothed observations HadCrut shows 0.02 C/decade NOAA/NCDC 0.06 C/decade and GISTtemp 0.12 C/decade, compared to IPCC’s multi model mean of 0.205 C/decade.

    Summary
    Using 2000 as the start date for analysis, and assuming red noise (i.e. “Phil Jones-like” noise) assumption to model residuals from a linear the multi-model mean trend under A1B forcing is inconsistent with observed trends based on NOAA and HadCrut, but remains ‘not-inconsistent’ with GISTemp. The 137 month (i.e. Jan 2000-May 2011) multi-model mean anomaly is inconsistent with all three observational data set if residuals are models using “red noise”; it is inconsistent with NOAA/NCDC and HadCRut but remains not-inconsistent with GISTemp if we use using maximal-uncertainty ARIMA to estimate the uncertainty intervals.

    It would be very helpful for some statistician to apply Lucia’s evaluation method to sea level data.

  25. Al Gored,
    Thanks for the link re: lowered sea floor adds .3mm/year in sea level. Oddly, I was just chatting with my husband and used a kiddy pool on loose dirt and soft grass to illustrate my skepticism about this adjustment. While the oceans may contain more water, the issue (I thought) was the peril of putting Manhatten Island and 2000 other islands, some inhabited, under water (to the surprise of the people who drowned because they didn’t get the memo).

    Willis, can you elaborate on the University of Colorado adjustment and their reasoning? Please remember, IANAS. Thanks in advance.

    Tom Rude, “In addition, Yin explained, if floating ice along the coastal areas melts it will allow the flow of glaciers to accelerate, bringing more ice into the seas.”
    Yin is saying that floating ice holds back glacier flow? I was under the impression that a 10′ deep reinforced concrete wall wouldn’t slow a glacier flow. I don’t understand. Any idea how Yin comes to this conclusion? Thanks in advance.

  26. This is an interesting example of alarmist science at it’s best. Yes, we definitely have to make sure that the enivronment is maintained, but we should not be giving out doomsday advice like it is popsicles.

  27. Hoser said: “Looks like the models all assume exponential increases.”

    This has been an underemphasized criticism of the AGW models. They are positive feedback models and therefore, are likely to produce exponential increases. The early growth of exponential models is very linear. So if you are fitting to the early part of an exponential increase to reality, projections to the very non-linear later portion of the curve are not valid as a description of that same reality.

  28. @Bob Johnson: There you go again sticking reality into the argument. Don’t you know reality does not matter when you have models?

  29. Wouldn’t you know it? All my life I cannot yet tell by looking at the coast to see if the sea level has risen, and now it’s dropping. No reason to get excited.

  30. Bob Johnston says:
    July 3, 2011 at 2:43 pm

    I’m a little confused and this may be a dumb question but…

    If this study was published in 2009 then weren’t all their projections known to be wrong at the time of publishing?

    You are quite correct, but you neglected to take into account that this was published in the vanity press laughingly known as the “Proceedings of the National Academy of Science”. They are famous for pal review, which is no review at all. In this case, Rahmstorf is a member of the inner circle of AGW supporters that roost at RealClimate, so (as clearly happened in this case) his writings will be given only the most cursory of peer reviews.

    w.

  31. OK,lets look at reality. Sea level has risen 0,00001 percent in the last 100 years. How the f*ck is that any kind of problem?

  32. SandyInDerby says:
    July 3, 2011 at 2:47 pm

    An interesting picture, as the house gives it scale. A rough estimate puts the house foundation 8 house-heights above the high-tide mark, which means a rebound of something like 30 metres over 10000 years, or 3mm per year. Over and above the sea level rise of something like 3mm/yr, therefore this part of Scotland’s coastline has risen 6mm/yr.

    As for the alleged drop in seabed of 0.3mm/yr, doesn’t erosion and sedimentation have any contrary effect?

  33. Willis I thought there were some interesting numbers in the 2010 BAMS State of the Climate Report (Oceans Sections/ Sea Level Variation).

    http://www.ncdc.noaa.gov/bams-state-of-the-climate/2010.php

    “Over this brief time period and in areas more than 200 km from the nearest coast where comparisons can be made with Argo and GRACE, the mean rate of total sea level rise is 1.5 ± 0.9 mm yr–1 (note that the uncertainties from here to the end of this section are 95% confidence levels). This rate cannot be compared with the global average over the entire altimeter time period cited above since at least 10 years of data are required to determine a reliable rate (Nerem et al. 1999). This rate is, however, in agreement (Fig. 3.29) with the sum (1.6 ± 0.6 mm yr–1) of the rates of the upper (depths < 700 m) ocean steric (0.5 ± 0.5 mm yr–1) and ocean mass components (1.1 ± 0.6 mm yr–1)."

    But best to ignore the numbers though.

  34. Yeah – you would’ve thought bright guys like that woulda noticed their model was already 30mm out at the time of publication! Sheesh! Did they think nobody would notice?

    I have aligned the Colorado observational results so that their trend line is zero in 1990, in order that they can be compared directly with the V&R2009 results.

    Why not just zero everything in 1992, the first year both datasets have in common? An easy process as the model numbers are in whole cm. The observations are available from 1992, with a trend of c3.1mm / year. So an offset of 6-7mm might be expected back to 1990, the graph here looks to have been shifted more like 10mm. Please explain.

    As you can see, the observations showed an actual sea level rise that is below the lowest of the V&R2009 estimates from the lowest of the IPCC scenarios.

    Here are the model numbers for A1F1 best and lowest in cm change since 1990:

    1992 1 1
    1993 1 1
    1994 1 1
    1995 2 1
    1996 2 1
    1997 2 2
    1998 2 2
    1999 3 2
    2000 3 3
    2001 4 3
    2002 4 3
    2003 5 4
    2004 5 4
    2005 6 5
    2006 6 5
    2007 7 5
    2008 7 6
    2009 8 6
    2010 8 7

    That is, a rise of 70mm or 60mm over 18 years. Or crudely, 3.9 or 3.3mm / year. The middle estimate is high, however the lower estimate is actually consistent with the UoC figure of 3.1 +- 0.4cm (itself the lowest-trending of the main indices), is it not?

    Speaking of ‘science content’, the sea level metric cited by V&R is from GRACE, (their ref 16). As they say,

    Another semiindependent test is provided by the satellite
    sea-level record updated from ref. 16 that started in 1993 and
    now provides 16 years of data (up including 2008), with a linear
    trend of 3.4 mm/year (after postglacial rebound adjustment).
    When the reservoir correction is applied it yields 3.6 mm/year,
    and the extra point is shown as an open circle in Fig. 4.

    Might be interesting to grab the GRACE data and graph that, as we are interested in apples v apples, no?

  35. Now with closed tag…

    Yeah – you would’ve thought bright guys like that woulda noticed their model was already 30mm out at the time of publication! Sheesh! Did they think nobody would notice?

    I have aligned the Colorado observational results so that their trend line is zero in 1990, in order that they can be compared directly with the V&R2009 results.

    Why not just zero everything in 1992, the first year both datasets have in common? An easy process as the model numbers are in whole cm. The observations are available from 1992, with a trend of c3.1mm / year. So an offset of 6-7mm might be expected back to 1990, the graph here looks to have been shifted more like 10mm. Please explain.

    As you can see, the observations showed an actual sea level rise that is below the lowest of the V&R2009 estimates from the lowest of the IPCC scenarios.

    Here are the model numbers for A1F1 best and lowest in cm change since 1990:

    1992 1 1
    1993 1 1
    1994 1 1
    1995 2 1
    1996 2 1
    1997 2 2
    1998 2 2
    1999 3 2
    2000 3 3
    2001 4 3
    2002 4 3
    2003 5 4
    2004 5 4
    2005 6 5
    2006 6 5
    2007 7 5
    2008 7 6
    2009 8 6
    2010 8 7

    That is, a rise of 70mm or 60mm over 18 years. Or crudely, 3.9 or 3.3mm / year. The middle estimate is high, however the lower estimate is actually consistent with the UoC figure of 3.1 +- 0.4cm (itself the lowest-trending of the main indices), is it not?

    Speaking of ‘science content’, the sea level metric cited by V&R is from GRACE, (their ref 16). As they say,

    Another semiindependent test is provided by the satellite
    sea-level record updated from ref. 16 that started in 1993 and
    now provides 16 years of data (up including 2008), with a linear
    trend of 3.4 mm/year (after postglacial rebound adjustment).
    When the reservoir correction is applied it yields 3.6 mm/year,
    and the extra point is shown as an open circle in Fig. 4.

    Might be interesting to grab the GRACE data and graph that, as we are interested in apples v apples, no?

  36. Now with closed bold tag…

    Yeah – you would’ve thought bright guys like that woulda noticed their model was already 30mm out at the time of publication! Sheesh! Did they think nobody would notice?

    I have aligned the Colorado observational results so that their trend line is zero in 1990, in order that they can be compared directly with the V&R2009 results.

    Why not just zero everything in 1992, the first year both datasets have in common? An easy process as the model numbers are in whole cm. The observations are available from 1992, with a trend of c3.1mm / year. So an offset of 6-7mm might be expected back to 1990, the graph here looks to have been shifted more like 10mm. Please explain.

    As you can see, the observations showed an actual sea level rise that is below the lowest of the V&R2009 estimates from the lowest of the IPCC scenarios.

    Here are the model numbers for A1F1 best and lowest in cm change since 1990:

    1992 1 1
    1993 1 1
    1994 1 1
    1995 2 1
    1996 2 1
    1997 2 2
    1998 2 2
    1999 3 2
    2000 3 3
    2001 4 3
    2002 4 3
    2003 5 4
    2004 5 4
    2005 6 5
    2006 6 5
    2007 7 5
    2008 7 6
    2009 8 6
    2010 8 7

    That is, a rise of 70mm or 60mm over 18 years. Or crudely, 3.9 or 3.3mm / year. The middle estimate is high, however the lower estimate is actually consistent with the UoC figure of 3.1 +- 0.4cm (itself the lowest-trending of the main indices), is it not?

    Speaking of ‘science content’, the sea level metric cited by V&R is from GRACE, (their ref 16). As they say,

    Another semiindependent test is provided by the satellite
    sea-level record updated from ref. 16 that started in 1993 and
    now provides 16 years of data (up including 2008), with a linear
    trend of 3.4 mm/year (after postglacial rebound adjustment).
    When the reservoir correction is applied it yields 3.6 mm/year,
    and the extra point is shown as an open circle in Fig. 4.

    Might be interesting to grab the GRACE data and graph that, as we are interested in apples v apples, no?

  37. 1DandyTroll sarcs:
    July 3, 2011 at 2:33 pm
    So, essentially, when the ocean floor sinks the sea rises even more. I can really visualize it: Mann and his schtick rising to even greater heights by the second in a pool of quicksand.
    ———-

    The sarcasm obscures your meaning but you do understand don’t you that if the sea floor falls the continents rise and vice versa .

  38. Ric Werne quoted Vermeer:
    =============================================
    … sea level rise would also contain a term proportional to the time derivative of temperature, dT/dt. In other words, global sea level would be a good global thermometer …
    =============================================
    He must have been reading Shaviv’s blog! He’s been there, done that:
    http://www.sciencebits.com/calorimeter

    Ah, there’s no better flattery than imitation.

  39. speaking of archiving and updating, does someone maintain an updated archive of all the predictions that have been made, with current measurements compared to predictions? It might be nice of Anthony would add such an archive, with a hot link to the right alongside the ENSO link and others.

  40. I’m not understanding the point of the .3mm/year adjustment. We live on LAND and if .3mm of water is added each year and the sea floor sinks .3mm a year then all of us on LAND could care less.

    If I run at 10 mph and the treadmill I’m on is going at 10 mph then I’ve moved no where. I’m not going to run from Los Angeles to New York if the treadmill I’m on is going in the opposite direction at the same speed. But with the proper ‘adjustment’ I can scare the people in New York that I’ll be there way way way way way way way sooner than reality.

  41. Jared says:
    July 3, 2011 at 5:54 pm

    I’m not understanding the point of the .3mm/year adjustment.
    =========================================================
    Jared, the slope/trend has been about .3mm/year, up until a few years ago.
    Then it stopped, like temperatures, and started going the other way – down
    This is the way they get their trend back from no trend…………..

  42. I would note that measurements claim that both the Atlantic and the Pacific are getting wider due to the ridges in each expanding. Is that shrinking the continents or squeezing them upward?? They need another correction for this!! Then again, maybe the land ISN’T rising due to the ocean bed getting deeper. They claim there is subduction also which could raise the continents and THAT is what is causing the rising. Maybe the land is rising without the basins getting deeper!! Of course, there is a fixed amount of material getting moved around here so it may really be zero sum and none of the above is actually happening on a long term basis. We are only seeing minor adjustments in the short term that reverse or are balanced over long periods!!

    Isn’t all this poorly measured information a wonderful thing for a poorly measured hypothesis of feedbacks causing a problem with temps??

  43. Hoser says:
    July 3, 2011 at 2:08 pm
    Oops, maybe we have a little problem there. US Dept. of Education, indoctrination of our kids at the expense of teaching. Cybersecurity, eventual replacement of internet with powerline broadband they control, probably like China.
    ==============
    So basically the socialists/greens/leftists own the media, education, the UN, most governments and much of the US gov.

    Quite the task to get through that. Not impossible, but we’ll all need to do some heavy lifting.

  44. LazyTeenager says:
    July 3, 2011 at 4:45 pm
    …”you do understand don’t you that if the sea floor falls the continents rise and vice versa .”…..
    ======
    Assuming your theory is true, what causes the rise and fall?

  45. Philip Clarke says:
    July 3, 2011 at 4:43 pm

    “Speaking of ‘science content’, the sea level metric cited by V&R is from GRACE, (their ref 16). As they say,

    Another semiindependent test is provided by the satellite
    sea-level record updated from ref. 16 that started in 1993 and
    now provides 16 years of data (up including 2008),”

    As I understand it the GRACE system was not launched until 2002 and it measures gravity not sea level elevation.

  46. I thank and congratulate Willis for this report on his interesting and important work. However, there is a logical shortcoming in the argument by which he reaches his conclusions that should be addressed.

    In Willis’s Figure 1, the yellow curves are examples of the entities that the IPCC calls “projections” (aka “scenarios”) but the entities which are logically comparable to observations are the entities that one calls “predictions.” While Figure 1 compares a number of projections from V&R’s model to a sea level time series, projections and observations are not logically comparable for unlike a prediction the set of projections does not state a falsifiable claim.

  47. LazyTeenager says:
    July 3, 2011 at 4:45 pm

    “… but you do understand don’t you that if the sea floor falls the continents rise and vice versa .”

    I’m only a geologist. Maybe you could explain this new theory to me? Maybe give some examples of where this is happening? Or is it just a model output?

  48. LazyTeenager says:
    July 3, 2011 at 4:45 pm
    1DandyTroll sarcs:
    July 3, 2011 at 2:33 pm
    So, essentially, when the ocean floor sinks the sea rises even more. I can really visualize it: Mann and his schtick rising to even greater heights by the second in a pool of quicksand.
    ———-

    The sarcasm obscures your meaning but you do understand don’t you that if the sea floor falls the continents rise and vice versa .

    ===============================

    DUH. But it is not that simple, lazy teenager.

    [Not sure why you would want that insulting, stupid moniker but hey who am I to judge.

    Sea level is a very very VERY complicated thing…and it has much much MUCH more to do with ocean floor sinking (or rising) and continent action of the same.

    Much, much, MUCH more.

    Stop being so lazy.

    Chris
    Norfolk, VA, USA

  49. Septic Matthew says:
    July 3, 2011 at 5:30 pm

    speaking of archiving and updating, does someone maintain an updated archive of all the predictions that have been made, with current measurements compared to predictions? It might be nice of Anthony would add such an archive, with a hot link to the right alongside the ENSO link and others.

    try this (as a starter):
    http://www.c3headlines.com/predictionsforecasts/

  50. Thanks again for another great post Willis! Re: your post on Tuvalu not sinking, I had the irritating displeasure of sitting next to a fellow who is paid to teach the people there how to deal with ‘climate change’, i.e. sinking, at a dinner the prior night to your post. Ironic.

    kuhnkat says:
    July 3, 2011 at 6:06 pm

    I would note that measurements claim that both the Atlantic and the Pacific are getting wider due to the ridges in each expanding. Is that shrinking the continents or squeezing them upward?? They need another correction for this!!
    I think you are right. They also need to consider that virtually all intersections of the ocean with land are on ground that slopes into the water. Therefore to increase sea level at a constant rate, an ever- increasing amount of water would have to be added to compensate for the wider ocean surface proportionate to the increasing depth. /sarc

  51. tokyoboy says:
    July 3, 2011 at 6:42 pm

    Is that a 60-year cycle? With a variation of about 60mm (not 300mm) over 100 years?? You mean, it’s *not* worse than we thought?

  52. Willis,

    I think you might want to disambiguate a couple of issues.

    1. Getting the forecast wrong because the model is wrong
    2. getting the forecast wrong because the inputs ( predicted temperature) is wrong.

    That is, instead of feeding their model Projected temps, feed it observed temps.

    That’s a test of the model. As it stands two issues are in play.

    Have you had any luck recreating their model?

  53. Technote 1 – The Colorado folks have recently included a 0.3mm/year increase in sea levels in their results. They say (possibly correctly) that this is necessary to adjust for the sinking of the ocean floor with the increasing weight of sea water from the melting at the end of the last ice age.

    If the ocean floor were rising, would the U Colo folks introduce a 0.3mm/yr decrease in sea level to compensate for it?

    To ask the question is to know the answer.

  54. M Carpenter says:
    July 3, 2011 at 2:38 pm . . . why is the angle . . .

    I guess you missed the theme of this post being about sea level and that the ice your link speaks of is floating ice?
    At the end of a glacial event the lower latitude and lower elevation ice will melt initially. Once the melting of this ice proceeds and leaves only high latitude and high elevation ice there isn’t going to be a lot of ice left that can easily be melted. Visit Seattle – look at “the Mountain.” Mt. Rainier still has glaciers (elevation) while the massive Puget Lobe (sea level) of the Frasier Glaciation is long gone. Oceans were about 400 feet lower then but the rise was rapid. Hope this helps.

    http://www.dnr.wa.gov/ResearchScience/Topics/GeologyofWashington/Pages/lowland.aspx

  55. Shanghai Dan says: about Neah Bay, Washington
    July 3, 2011 at 2:13 pm

    That might just be a sign that the coast of Washington is warping up as this is an active plate margin. If you are young enough and live to be elderly you might be around when the locked sections fail and the coast sinks about 10 feet. Then again, this might happen tomorrow or next week. Spend an hour at the PANGA site:
    http://www.geodesy.cwu.edu/

  56. steven mosher says:
    July 3, 2011 at 9:52 pm

    Willis,

    I think you might want to disambiguate a couple of issues.

    1. Getting the forecast wrong because the model is wrong
    2. getting the forecast wrong because the inputs ( predicted temperature) is wrong.

    That is, instead of feeding their model Projected temps, feed it observed temps.

    That’s a test of the model. As it stands two issues are in play.

    Have you had any luck recreating their model?

    Very nice, Mosh, good questions. I’ve been moving quite fast and haven’t looked at their model. Just back from a gorgeous night out on the banks of the river, 70°F (20°C), fireworks, a constant parade of geeks and freaks walking and bicycling and driving and biking and wheelchairing past. One of the most perfect 4th of Julys in my memory.

    As time permits I may take a look at their model. I have lots going on.

    w.

  57. “This paper adds to the evidence that we could have sea level rise by the end of this century of around 1 meter and a good deal more in succeeding centuries.” ))

    And where is all this evil carbon based energy to come from to “pollute” the atmosphere you moron.??????…..(stand back, take a deep breath)
    regards

  58. Mike Jowsey says: July 3, 2011 at 9:48 pm
    “Is that a 60-year cycle? With a variation of about 60mm (not 300mm) over 100 years??”

    Well our Met Office says just two things:
    1. There’s no long-term trend in the past >100 years.
    2. About 20-year cyclic oscillation is evident.

  59. The graph you present here seems to show a precipitous drop at the end which is more to do with your scaling than anything else
    http://climate.nasa.gov/keyIndicators/index.cfm#seaLevel
    This is NASA/NOAA version of the same data it does show a dip starting near the beginning of 2011 which you may have heard had a cool start much the same as as 2008 did (it shows a similar dip and if you look at 1998 (in the Colorado graph) you see a spike.

    It is a thermal signature as sea level rise is part thermal expansion and part melting ice and yes 2011 started cool, but it is warming and the Colorado data shows that as the small arrest in the most recent of their data, which strangely seems to not show in your version.
    More interesting would be why your graph shows sea level dropping to the equivalent of 2007 levels when NOAA’s only have a dip equal to late 2010 with both these points being well above 2007, 2008 or 2009 levels.
    It is interesting to see you say the IPCC estimates are “realistic ” I would actually agree with that, but I think many others here wont.

    @mike g says:
    July 3, 2011 at 1:26 pm

    re: @fredb
    Yes, what a silly comment. It’s been upwards since the last ice age. And, we’re supposed
    to be alarmed that it continues to do what it’s done for thousands of years?

    I hope you mean up ~2000 years ago, or don’t you count that bit

  60. Steven Mosher: model looks pretty simple. wonder why they just dont supply code

    They did. In the SI to the paper. Cunningly hidden away in an archived mischieviously entitled ‘Sea Level Code’

    http://www.pnas.org/content/early/2009/12/04/0907765106/suppl/DCSupplemental

    Anyone actually reading the paper also discovers a model/obs data comparison covering the satellite era. I’m curious: do you agree that V&R went to press with a model that was 3cm out at the time of publication, and it got into the literature solely due to sloppy peer review?

  61. u.k.(us) says:
    July 3, 2011 at 6:24 pm
    LazyTeenager says:
    July 3, 2011 at 4:45 pm
    …”you do understand don’t you that if the sea floor falls the continents rise and vice versa .”…..
    ======
    Assuming your theory is true, what causes the rise and fall?
    ———————-
    when we entered the current interglacial the ice on land melted. Less weight on land and more weight on the ocean floor.

    The continents and oceans together behave like a seesaw or even better a water bed. You shift weight from one side to the other so one side goes down the other side goes up

    It is a bit hard to visualize if you are not accustomed to thinking of solid rock as a very viscous fluid.

  62. Compensation for increased water column seems to me to include an unnecessary correction. Compared to the weight of the lithosphere the water column is negligible and extra water from ice melt smaller still. Oceans deepen from the ridge system, where new ocean bed is being produced, due to lithospheric thermal contraction ie. cooling as it moves away from the ridge.

  63. “The sea floor moves down, the continents move up”. That is correct. Look up isostacy, essentially equilibirium. The mechanism is loading of one area of crust will cause subsidence, and displace the equivalent mass of mantle causing uplift elsewhere.

    On a longer time scale, the area of the oceans remains relatively constant through time, but the volume does not. The mechanism here is the rate of sea floor spreading. As newly formed oceanic crust moves away from spreading centres it cools and shrinks, the oceans essentially get deeper away from the ridges. When spreading rates are high, a greater proportion of hot crust is preserved and sea levels are high. Vice versa for periods of low spreading rate.

    This from my undergraduate days at UEA, in a time long, long ago, when they taught science.

  64. Ditto with temperature. At which point are we going to scrap the IPCC? It is as useful to policy makers as used toilet paper.

    We must act now!

  65. Chris from Norfolk va reckons
    —–
    Sea level is a very very VERY complicated thing…and it has much much MUCH more to do with ocean floor sinking (or rising) and continent action of the same.

    This is rather ambiguous Chris.

    I did reread my post Chris and as far as I can tell there is no indication that I am claiming that sea floor movement is the only factor affecting sea level. I did offer an explanation of just one contributing factor out of many.

    I hope you are no longer confused.

  66. In the opening graph the worst case scenario was 10cm rise in 20 years and the actual observed rise was 5cm. That ain’t all that bad of a guess IMO even though an octopus would have likely guessed as well. The problem is that these model predictions are couched with far more certainty than they deserve. At the end of the day they are no more or no less than the proverbial “educated guess”. The problem with educated guesses nowdays is education in some instances has become more like indoctrination whereby the guesses are steered more by
    ideology than objectivity.

  67. How does this square with Greenland’s ‘record’ meltdown, WAIS ‘Armageddon’ crack ice, the dissolving glaciers around the world in the hottest decade on the record? Am I using my common sense correctly or is increased rate of sea level rise in the pipeline? ;o)

  68. I’m still trying to get my head round this new theory that the real sea level rises are being masked by the falling sea bed that results from the weight of all this melting ice. As this melting ice has been occurring since the end of the ice age, why is the falling sea bed only now begun to mask the rising sea levels?

    To be even more specific, the sea levels were measured to be rising at a rate of about 3mm per year – until about 6 years ago, then stopped rising. Does it mean that the rate of fall of sea bed has increased by 3mm per year since then, and if so, why would that be?

  69. Yes, the floor may be sinking, but it is also rising. Else why do we take core samples to help us proxy changing conditions by studying all the stuff that falls onto that sinking floor?

  70. Isotasy is not a new theory. Fred Vine (Professor of Geophysics at UEA, Vine and Matthews 1964, the man who interpreted magnetic stripes as sea floor spreading) ran through isostasy (Airey model vs McKenzie model) very nicely. This was in about 1982. Sea level change is not simple. It is very very complex.

  71. Jared says:
    July 3, 2011 at 5:54 pm

    I’m not understanding the point of the .3mm/year adjustment. We live on LAND and if .3mm of water is added each year and the sea floor sinks .3mm a year then all of us on LAND could care less.

    What follows is quite a banal analogy but it’s all I could think of, so here goes:
    Imagine you’re pulling some cable out of a hole in a wall and want to know how much you’ve pulled out. You could find out by measuring from the wall to the end of the cable you’ve pulled through.

    Imagine now that someone comes in every few minutes and snips a couple of centimetres off the end of the cable. Your measurement methodology is now inadequate because the length of the cable on your side of the wall has been affected by something other than the amount you’ve pulled through. You will need to find out how much has been snipped to calculate the correct figure.

    Hopefully you can see how this fits measurement of sea level. When people talk about sea level change what is measured is essentially the height of the sea. If, say, the sea floor drops our measurements will show the sea reducing in height but that’s not what actually happened. To get the true height of the sea you need to account for the sea floor drop.

    Whether you apply the adjustment or not depends on what you want to measure. Obviously it’s not relevant if you just want to find out the sea level relative to your local city at any one point in time, for reasons of flood risk assessment etc. Likewise if you only want to find out how much continuous cable is extruding from the hole in the wall the basic measurement is fine. It’s only when you want to find the total amount pulled through that you have to make further adjustments.

    If you want to construct a time series of changing sea height you need to account for any factors that will bias the measurements.

  72. Willis, none of these sea level data are corrected for water held in storage as they should be. Chao, Yu, and Li (Science April 11th 2009) did that for more than 70,000 impoundments built since 1900 and discovered that when these corrections were applied to published sea level curves the sea level rise became linear for the last 80 years or more. Something that has been linear for more than 80 years is not likely to change anytime soon. The slope of that curve was 2.46 millimeters per year which is 24.6 cm or just under ten inches per century. I think all these newly published data should have the impoundment correction applied to them and then compared to Chao, Yu, and Li. Theirs is the most believable long term sea level record we have. Things like melting glaciers or the effect of sea bottom responding to glacial loads are already subsumed into their long term curve and should not be used to confuse the issue. Any observations that deviate from linearity should be viewed with suspicion. And any predictions of accelerating sea level rise should be labeled for what they are – alarmist attempts to falsify our climate future.

  73. Talk to people in Emsworth (Amoung others), Hampshire, England. Hundreds of years of…errrmmm…nothing in terms of sea level rises. Unless of course, the LAND rose at EXACTLY the SAME rate of sea level rise (Or near too it)! Huh?

  74. Natural plate tectonics causes of order one to a few millimeters per year change in the continental landscape. If the motion is vertical then any sea level rise, more water in the oceans, will be offset by centimeters of continental rise over ten to thirty year periods. Presumably modelers correct for this, if they are honest.

    Also, a question, if the glaciers melt, then the continents will weigh less, so they should float higher on the mantle. This would tend to offset, and decrease the effective sea level rise for land use planning.

    Is this mechanism related to “bounce” the U of Colorado research unit is talking about?

  75. RoHa said: So …. we’re not doomed?

    Oh no, we’re still doomed, we just need to find out the mechanism. But rest assured, we are doomed!

    John F. Hultquist said: That might just be a sign that the coast of Washington is warping up as this is an active plate margin.

    Precisely the point. We’re not stable at all, and claiming that a rising OR falling sea level is a disaster is simply ludicrous. Even in my other home, Shanghai, we see changes in land elevation from subsidence and pressures well beyond the supposed 1mm per year. The land itself is changing at a rate faster than the oceans, yet the concern is over the ocean’s average elevation (as if such a thing could be calculated).

    I submit that worrying about a millimeter a year of change in average ocean level is a waste of time; better to worry about things that will affect people in the next 200-300 years like power, pollution, fresh water, and food. By the time water elevations could possibly change enough to impact huge, low-lying areas like the Shanghai/Yangtze basin (which would need a 40-50 cm rise), we’ll have many, many more problems to overcome first.

    But then again, fresh water and power restrictions aren’t as fear-mongeringly-huge sounding of a problem as flooding from the rising ocean levels…

  76. Hi Willis,

    I have never posted on this site before, but I was quite interested in the Rahmstorf paper when it came out. I looked into it at that time and thought it was very weak. The update with Vermeer was little better. I had been thinking about looking at this lately because my intuition was that they had done poorly so far. But actually your graph doesn’t really show how poorly. Their formulas are attempts to predict the rate of sea level change, not sea level. So if you really want to see what is happening you would have to take the years since their paper was published and look at their predicted rate of change versus the actual. They also have little excuse for this to be a short term issue since their formula assumed that the rate of change was predicted from the temperature deviation from a baseline temperature, and that deviation has continued throughout the period (although it hasn’t increased). My original blog post on this topic is;

    And now my usual disclaimer. I think the IPCC AR4 is good overall. Their paper attempted to say that that report was wrong. I am actually just going with the consensus view on this, as I tend to on this entire issue.

    http://nierenbergclimate.blogspot.com/2009/04/published-comments-on-rahmstorf-2007.html

  77. @ Pamela Gray says:
    July 4, 2011 at 9:20 am

    Pamela, is there any peer reviewed study with indicates how muck sediment is replacing the subsiding sea bottom?

  78. In climate science rule one rule states , that when the model and reality differ in value its reality which is in error . So there is no problem the sea levels have increased as predicted as the models prove . The physical level of the sea has no bearing on this.

  79. The reason the Colorado Plateau has risen for the past 10my is that sediment has been eroded from it. This continental lift compensates for the sedimentation which of itself of course would tend to raise the sea level. So no, sedimentation will not reverse the GIA. What about impoundment? This is more than made up for by groundwater depletion in developed continents, and remains a minor contribution.

    But I repeat like a broken record: LOD constrains our interpretation of sea level rise, about .1ms/cm rise, and no such LOD increase is witnessed. Lately mentioned hydrate contribution from the mantle is a very interesting subject which I knew nothing about–I’ll stay tuned to any further commentary on this.

    I for one, am interested in knowing how deep is the ocean–not just how high–and I don’t feel threatened by CU’s adjustment. –AGF

  80. Shanghai Dan says:
    “Oh no, we’re still doomed, we just need to find out the mechanism. But rest assured, we are doomed!”

    Phew!

    Thanks. I like to get these things clear.

  81. David says:

    “Pamela, is there any peer reviewed study with indicates how muck sediment is replacing the subsiding sea bottom?”

    Sequence stratigraphy is used universally in the oil industry for interpreting marine seismic data. There are masses of published papers on it. Search “Vail sequence stratigraphy”.

    Start with the SEPM here: http://sepmstrata.org/history/vail.html

  82. What is modeling, anyhow? Good question. Generally, in the physical sciences and elsewhere, “Modeling” is a term that has a specific meaning. Namely modeling is a procedure for numerical fitting and interpolation of existing sets of observational data. Such modeling aims to provide a simplified analytic function or set of functions that match discrete data points and interpolate between them. A mathematical property of such models is their neighborhood of convergence around the data set. Usually the size of the neighborhood of convergence (or validity) is not known exactly. It can be estimated. In this discussion, we view data as a collection of discrete points embedded in an abstract continuum parameter space. Independent variables might be time, physical location, etc. Dependent variables, are the quantities for which observations exist in the data set. So temperature, or the non-thermodynamic quantity “global average temperature” we hear about would be examples of dependent variables.

    Models are validated by measuring a “goodness of fit” to the data base. If the model parameters can be adjusted to fit the existing data to some desired degree of accuracy it is considered a validated model. It is usually not considered valid outside it’s range of validation. e.g. John von Neumann’s Elephant.

    What about extrapolation? Often, modelers are asked to extrapolate their models beyond the validated data base. Into the unknown future, or elsewhere. These extrapolations are notoriously un-reliable for several reasons, among them are (1) the fact that models do not obey causality, (2) they may not properly conserve invariants of the underlying physical system, (3) are often mathematically unstable and exhibit divergent behavior in the limit of large dependent variable, (4) non-linear regression fits used in climate modeling are especially prone to instability. Such instabilities would inevitably “predict” catastrophic values of the dependent variables as an artifact of their instability.

    Modelers often spice up the mix by invoking sets of model equations that may be solved numerically to propagate the model into the future. Such model equations may have some physics in them, but inevitably they leave out important physical processes. If they included the real physics of the complete system, they would be simulations, not modeling. Simulations obey causality, and usually consist of sets of time dependent PDEs that are directly obtainable from underlying physical laws.

    Running long here, but in most fields of physics, models are considered useful tools for data analysis, but their known limitations in range of validity are widely appreciated. There are just too many ways for extrapolations to go wrong.

    For these reasons, we question the methodology of climate modeling. It seems too much weight is given to unreliable extrapolations beyond the mathematical range of validity of such models.

    Of course, everyone knows all of this. So why are climate models treated as infallible when the methodology is known to be unreliable for extrapolation?

    Maybe that’s enough for the moment. Responses welcome. A little dialog is a good, but let’s keep it on the top two levels of the Graham hierarchy.

  83. ‘However, since neither the IPCC nor the V&R2009 figures include [GIA] adjustment, I have not included it in this analysis so that we can compare apples to apples.’

    V&R2009 is an investigation into the link between sea level and temperature. To test their model you need to remove any known non-climatic causes of sea level change. That means applying the GIA correction and the Chao 2008 reservoir adjustment, which are both mentioned in V&R2009. They wouldn’t be explicitly included in the projection figures because the adjustments are purely a means to correct biases in physical measurements.

    Your ‘observations’ curve also looks very wrong at the end. I think the problem is there are only 3 datapoints (usually about 36 for a year) in 2011 so far and you’ve placed too much weight on a small amount of data. At this point you should probably ignore 2011 altogether.

    I plotted the Church & White 2011 tide gauge and altimeter data (http://www.psmsl.org/products/reconstructions/church.php) against the V&R2009 projection. This data includes the GIA already and I applied a 0.2mm/yr adjustment on top to simulate the reservoir adjustment. That represents a fair test of the model projections. The data only goes up to 2009 but, by reference to the Colorado data, you can add about 0.8mm on top pf the 2009 figure to get a 2010 approximation.

    Looking at my plot the observations are skirting along the lower projection. At this point I think it can be inferred that the V&R2009 model is maybe a little too ‘hot’. For those talking about the IPCC projections I placed them on the same graph and they are nowhere near observations. That said I’m not sure whether or not it’s appropriate to apply GIA and reservoir adjustment for comparison with the IPCC projections since they’re presumably trying to determine what will be the overall sea level change relative to land, regardless of causation.

  84. It seems there is a developing consensus that Climate Models are almost as reliable as two parameter Linear Regression at predicting the future.

  85. The local media in the San Francisco metro have latched onto a notion of “a 55 inch rise by 2100!”

    That is in spite of the falling sea level as measured at the Ft. Point tide gauge.

    Ask any port around here if their dredging budget is decreasing.

    Nonetheless, the meme is now out there and soon there will be takings on a scale that no environmental regs could ever achieve, e.g. being deemed in a future intertidal zone.

  86. @LazyTeenager says:
    July 4, 2011 at 2:20 am re: “viscous”. The only thing viscous here is your brain. Why do you waste people’s time here with your simpleton comments?

  87. Models cannot predict anything because they do not obey causality. Models are inherently unreliable in extrapolation beyond their validated domain. Models nearly always unstable when independent variables are extrapolated beyond their validated domain. Models are usually unstable when extrapolated. This model generates catastrophic “predictions” as an artifact of this instability. More on this at http://syntheticinformation.blogspot.com/2011/07/what-is-modeling.html a draft version of a “think piece” on Modeling and its Inherent Limitations. Hope its ok to mention it here.

  88. New revised and polished version of a think-piece on Modeling and Simulation. It’s not titled “Why Climate Models Suck” but I suppose it could be. More accurately, we discuss modeling in the abstract. Highlight the non-causal nature of Climate Models and discuss the inherently unreliability upon extrapolation of models beyond their range of validation.

    TY to WUWT for allowing me to mention this new relevant blog article…. http://syntheticinformation.blogspot.com/2011/07/what-is-modeling.html

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